Insecticide-treated bed nets (ITNs) have been shown to significantly reduce malaria related morbidity and all cause child mortality across a range of transmission settings. Zambia has recently launched an unprecedented scale-up of free ITN distribution with the target of distributing 3 million long-lasting ITNs by the end of 2007. However, the impact of ITNs on preventing malaria morbidity and mortality will be minimized if they are not properly and consistently used, especially among children and pregnant women. Our long-term goal is to provide public health scientists and officials with an effective intervention to optimize ITN uptake and use among children and pregnant women as they become more widely available through the scale-up of national distribution programs. It is hypothesized that a village-based interpersonal communication (IPC) intervention will increase ITN use among households already possessing them within the context of a national ITN distribution program currently underway in Zambia. The focus of this application is to: 1) test if a village based IPC intervention increases the proportion of children using ITNs within households possessing them within the context of a large-scale ITN distribution program in the Luangwa District of Zambia;2) determine the costs associated with achieving such increased ITN use;and 3) identify household, community and policy-level factors that facilitate or impede ITN use among children. A group randomized controlled trial will be used to assess the effectiveness of the IPC intervention at increasing ITN use among children within households possessing at least one ITN, relative to children within households possessing at least one ITN within non-IPC intervention villages in the Luangwa District of Zambia. The primary outcome measure will be the proportion of children under five years old using an ITN within households possessing at least one ITN. The IPC intervention will be delivered by community health workers face-to-face in villages, and will focus primarily on: 1) repeated demonstrations of proper ITN deployment and use;and 2) written, verbal and video communication as to the health-related benefits of ITNs to children. An incremental cost-effectiveness analysis will be conducted to determine the ratio of costs to effectiveness of the IPC intervention at increasing ITN use relative to the control of non-IPT villages. Immediate ways that our research will have a direct and significant scientific and societal impact include: 1) Our IPC activities to increase ITN use will provide a basis for determining when, where and what types of messages should be used to achieve the greatest impact on ITN use in similar setting in Africa;2) Positive results can potentially lead to the development of behavioral interventions strategies to increase adoption of other efficacious malaria control interventions in Africa;and 3) Our project emphasizes the identification of impediments and facilitators to ITN adherence and the translation of results into public health policy;the methods employed can serve as a model to promote interdisciplinary approaches for research and problem solving in Africa.